Aaron Lloyd Evans-Keady, 26, conspired with a civilian detention officer, Keiran Cross, 24, to falsify drug test results on cocaine found on an arrested woman so they appeared negative.

Passing sentence at Southwark Crown Court today, a judge described the offence as “deplorable” and a “gross breach of trust”.

The arrested woman was taken to Kentish Town Police Station by Evans-Keady, where Cross, a designated detention officer, carried out a routine test on the drugs.

The court heard how Evans-Keady, who had been receiving trauma counselling, took pity on the arrested woman.

He said to Cross “She’s not the normal slag you see and I feel sorry for her” and asked what could be done.

It is thought Cross suggested recording a negative result on the drug test so the woman would avoid being charged.

The incident happened on January 28 last year when Evans-Keady arrested a woman in possession of three small wraps of cocaine in Camden.

Cross, who was suffering from depression after accruing £25,000 of gambling debts, confessed to senior officers almost immediately about what had happened.

He was handed a suspended sentence of two years and ordered to carry out 250 hours community service.

Evans-Keady, who had qualified as a police officer just a year earlier, initially denied any wrong-doing but later changed to a guilty plea before the start of his trial.

He was sentenced to two years in prison.

Defence lawyers argued their behaviour was a “moment of madness” and neither defendant had anything to gain from lying about the test results, but “everything to lose”.

His Honour Judge Higgins said: “Such behaviour by a police officer is both deplorable and deeply anti-social and represents a gross breach of trust that strikes right to the heart of the criminal justice system. It can’t and will not be tolerated.”

He added: “How could the public place any trust in the police force if officers behaved as you have?”